The general preparation of silver nanowires (10-200 aspect ratio) is known. See, for example, Angew. Chem. Int. Ed. 2009, 48, 60, Y. Xia, Y. Xiong, B. Lim, S. E. Skrabalak, which is hereby incorporated by reference in its entirety. Filtration and centrifugation technologies are known. See, for example, Chemical Engineers' Handbook, 5th ed., R. H. Perry and C. H. Chilton, eds., McGraw-Hill, 1973, pp. 19-57 to 19-98, which is hereby incorporated by reference in its entirety. Methods of fabricating devices with transparent layers comprising silver nanowires are described in, for example, Liangbing Hu, Han Sun Kim, Jung-Yong Lee, Peter Peumans and Yi Cui, “Scalable Coating and Properties of Transparent Flexible, Silver Nanowire Electrodes”, ACS Nano, 2010, 4 (5), 2955-2963, (available at www.stanford.edu/group/cui_group/papers/Transprent %20Ag.pdf), and Anuj Madaria, Akshay Kumar, Fumiaki Ishikawa, and Chongwu Zhou, “Uniform Highly Conductive, and Patterned Transparent Films of a Percolating Silver Nanowire Network on Rigid and Flexible Substrates Using a Dry Transfer Technique,” Nano Res., 2010, 3, 564-573, and Xiao-Yan Zeng, Qi-Kai Zhang, Rong-Min Yu and Can-Zhong Lu, “A New Transparent Conductor: Silver Nanowire Film Buried at the Surface of a Transparent Polymer,” Adv. Mater., 2010, 22, 4484-4488, all of which are incorporated by reference in their entirety.